Graphical user interface for a display screen or portion thereof



FIG. 1 is a front view of a graphical user interface for a display screen or portion thereof showing our new design; and,

FIG. 2 is a front view of a second embodiment thereof.

The OpenPeak trademark in the upper left corner of each of the figures is the property of OpenPeak Inc. Trademarks are the property of their respective owners.

The broken line showing of the display screen or portion thereof in the figures is not part of the claimed design. 

The ornamental design for a graphical user interface for a display screen or a portion thereof, as shown and described. 